gogo-telefon/gogo/telephony/asterisk.py

"""Asterisk configuration generator (M4): pjsip.conf + extensions.conf.

Generated from the DB (tenants, workers) so the dashboard stays the single
source of truth. Ring-group-first logic (§5.2) lives in the dialplan, but the
decision (targets + timeout, working hours) comes from the backend via the
internal API at call time — Asterisk never duplicates tenant config.

Usage:  python -m gogo.telephony.asterisk --out ./asterisk/conf
Regenerate + `asterisk -rx 'core reload'` whenever workers change.
"""

from __future__ import annotations

import asyncio
import sys
from pathlib import Path

from sqlalchemy import select

from gogo.config import get_settings
from gogo.db import get_sessionmaker
from gogo.models import PhoneNumber, Tenant, Worker


def gateway_line_password(msisdn: str) -> str:
    """Deterministic per-SIM SIP secret (no extra storage; derived from the app key)."""
    import hashlib

    return hashlib.sha256(
        f"{get_settings().secret_key}:gw:{msisdn}".encode()
    ).hexdigest()[:16]

PJSIP_HEADER = """\
; -- generated by gogo.telephony.asterisk — do not edit by hand --

[global]
type=global
user_agent=GogoTelefon

[transport-udp]
type=transport
protocol=udp
bind=0.0.0.0:5060
"""

ENDPOINT_TEMPLATE = """\

; worker: {name} ({tenant})
[{username}]
type=endpoint
context={context}
disallow=all
allow=alaw,ulaw,slin
auth={username}-auth
aors={username}
direct_media=no
rtp_symmetric=yes
force_rport=yes
rewrite_contact=yes

[{username}-auth]
type=auth
auth_type=userpass
username={username}
password={password}

[{username}]
type=aor
max_contacts=3
remove_existing=yes
"""

# GSM gateway SIP trunk (M5): each SIM line registers as its own endpoint and
# lands directly in its tenant's inbound context (1 SIM = 1 salon, §5.1).
GATEWAY_LINE_TEMPLATE = """\

; GSM gateway line {port} → {msisdn} ({tenant})
[gw-line-{port}]
type=endpoint
context={context}
disallow=all
allow=alaw,ulaw
auth=gw-line-{port}-auth
aors=gw-line-{port}
direct_media=no
rtp_symmetric=yes
force_rport=yes
rewrite_contact=yes

[gw-line-{port}-auth]
type=auth
auth_type=userpass
username=gw-line-{port}
password={password}

[gw-line-{port}]
type=aor
max_contacts=1
remove_existing=yes
"""

# Test endpoint for M4 software-only testing: a desktop softphone registers as
# 'test-caller' and dials any number to reach the tenant's inbound flow (§16 M4).
TEST_CALLER_TEMPLATE = """\

; software-testing caller (softphone) → lands in {context}
[test-caller-{slug}]
type=endpoint
context={context}
disallow=all
allow=alaw,ulaw,slin
auth=test-caller-{slug}-auth
aors=test-caller-{slug}
direct_media=no
rtp_symmetric=yes
force_rport=yes
rewrite_contact=yes

[test-caller-{slug}-auth]
type=auth
auth_type=userpass
username=test-caller-{slug}
password={password}

[test-caller-{slug}]
type=aor
max_contacts=3
remove_existing=yes
"""

EXTENSIONS_HEADER = """\
; -- generated by gogo.telefonija.asterisk — do not edit by hand --

[globals]
GOGO_BACKEND={backend}
GOGO_VOICE={voice}
GOGO_TOKEN={token}

[gogo-workers]
; workers only receive calls in MVP
exten => _X.,1,Hangup()
"""

TENANT_CONTEXT_TEMPLATE = """\

[{context}]
; inbound flow for {tenant_name} (§5.2): register → ring staff → agent fallback
exten => _[+0-9].,1,NoOp(Gogo inbound ${{EXTEN}} for {slug})
 same => n,Answer()
 same => n,Set(REG=${{CURL(${{GOGO_BACKEND}}/internal/calls/register?tenant={slug}&caller=${{URIENCODE(${{CALLERID(num)}})}}&token=${{GOGO_TOKEN}})}})
 same => n,GotoIf($["${{REG}}"=""]?fallback)
 same => n,Set(GOGO_UUID=${{CUT(REG,\\,,1)}})
 same => n,Set(RINGTIME=${{CUT(REG,\\,,2)}})
 same => n,Set(TARGETS=${{CUT(REG,\\,,3)}})
 same => n,GotoIf($["${{TARGETS}}"=""]?agent)
 same => n,Dial(${{TARGETS}},${{RINGTIME}})
 same => n,GotoIf($["${{DIALSTATUS}}"="ANSWER"]?answered)
 same => n(agent),AudioSocket(${{GOGO_UUID}},${{GOGO_VOICE}})
 ; if the voice pipeline is down AudioSocket fails instantly → fallback (§15);
 ; after a normal agent call the caller is gone and Playback is a no-op
 same => n,Playback(gogo-fallback)
 same => n,Hangup()
 same => n(answered),Set(RES=${{CURL(${{GOGO_BACKEND}}/internal/calls/${{GOGO_UUID}}/answered?token=${{GOGO_TOKEN}}&duration=${{CDR(billsec)}})}})
 same => n,Hangup()
 same => n(fallback),Playback(vm-goodbye)
 same => n,Hangup()

; caller hung up mid-flow (e.g. while ringing) → missed-call handling (§5.5)
exten => h,1,GotoIf($["${{GOGO_UUID}}"=""]?done)
 same => n,Set(RES=${{CURL(${{GOGO_BACKEND}}/internal/calls/${{GOGO_UUID}}/hangup?status=${{DIALSTATUS}}&token=${{GOGO_TOKEN}})}})
 same => n(done),NoOp(bye)
"""


async def generate(out_dir: Path, backend_url: str = "", voice_addr: str = "") -> list[str]:
    """Write pjsip.conf + extensions.conf; returns list of written files."""
    s = get_settings()
    backend_url = backend_url or "http://backend:8000"
    voice_addr = voice_addr or f"voice:{s.voice_port}"

    pjsip = [PJSIP_HEADER]
    extensions = [
        EXTENSIONS_HEADER.format(backend=backend_url, voice=voice_addr, token=s.internal_token)
    ]

    async with get_sessionmaker()() as session:
        tenants = (
            (
                await session.execute(
                    select(Tenant).where(Tenant.status == "active").order_by(Tenant.slug)
                )
            )
            .scalars()
            .all()
        )
        for tenant in tenants:
            context = f"gogo-inbound-{tenant.slug}"
            workers = (
                (
                    await session.execute(
                        select(Worker)
                        .where(Worker.tenant_id == tenant.id, Worker.active.is_(True))
                        .order_by(Worker.sip_username)
                    )
                )
                .scalars()
                .all()
            )
            for w in workers:
                pjsip.append(
                    ENDPOINT_TEMPLATE.format(
                        name=w.name,
                        tenant=tenant.slug,
                        username=w.sip_username,
                        password=w.sip_password,
                        context="gogo-workers",
                    )
                )
            pjsip.append(
                TEST_CALLER_TEMPLATE.format(
                    slug=tenant.slug,
                    context=context,
                    password=f"test-{tenant.widget_public_key[:10]}",
                )
            )
            extensions.append(
                TENANT_CONTEXT_TEMPLATE.format(
                    context=context, tenant_name=tenant.name, slug=tenant.slug
                )
            )

            # GSM gateway line for this tenant's SIM (M5)
            number = (
                await session.execute(
                    select(PhoneNumber).where(PhoneNumber.tenant_id == tenant.id)
                )
            ).scalar_one_or_none()
            if number and number.gateway_port is not None:
                pjsip.append(
                    GATEWAY_LINE_TEMPLATE.format(
                        port=number.gateway_port,
                        msisdn=number.msisdn,
                        tenant=tenant.slug,
                        context=context,
                        password=gateway_line_password(number.msisdn),
                    )
                )

    out_dir.mkdir(parents=True, exist_ok=True)
    written = []
    for filename, content in [
        ("pjsip.conf", "".join(pjsip)),
        ("extensions.conf", "".join(extensions)),
    ]:
        path = out_dir / filename
        path.write_text(content)
        written.append(str(path))
    return written


def main() -> None:
    out = Path("./asterisk/conf")
    backend = ""
    voice = ""
    args = sys.argv[1:]
    while args:
        arg = args.pop(0)
        if arg == "--out" and args:
            out = Path(args.pop(0))
        elif arg == "--backend" and args:
            backend = args.pop(0)
        elif arg == "--voice" and args:
            voice = args.pop(0)
    written = asyncio.run(generate(out, backend, voice))
    for path in written:
        print(f"wrote {path}")


if __name__ == "__main__":
    main()